Dissertations, Theses, and Capstone Projects

Date of Degree

2-2022

Document Type

Dissertation

Degree Name

Ph.D.

Program

Physics

Advisor

Carlos Meriles

Committee Members

Igor Kuskovsky

Maria Tamargo

Swapan Gayen

Vinod Menon

Subject Categories

Condensed Matter Physics | Optics | Quantum Physics | Statistical, Nonlinear, and Soft Matter Physics

Keywords

quantum information, valleytronics, paul trap, NV center, charge transport

Abstract

Solid state defects in diamond are promising candidates for room temperature quantum information processors (1, 3, 5). Chief among these defects is the nitrogen vacancy center (‘NV center’ or ‘NV’). The NV has long coherence times (at 300K) and its state is easily initialized, manipulated and read out (5). However, the outstanding issue of entangling NV centers in a scalable fashion, at room temperature remains a challenge. This thesis presents experimental and theoretical work aimed at achieving this goal by developing the ‘flying qubit’ framework in (1). This method for remote entanglement utilizes a charge carrier (initialized into a definite spin state) that is ionized from an NV. The carrier is transported through the diamond and captured by a remote defect where its state may be correlated with the initial qubit. Here, we present the results of charge transport experiments both in ensembles of NVs and in precision engineered samples aimed at examining the potential of this concept. We find that space charge effects greatly impact the charge carrier dynamics in ensembles and may be useful for channeling or guiding charge carriers to remote defects. What is more, we show inter-defect transport on the single NV level and derive important parameters of the process (e.g., capture cross section). We also examine the possibility of using electrodynamic fields to tightly confine charge carriers during transit inside the crystal. While we find that this method (Paul Trapping) is unlikely to be fruitful for the flying qubit project, it may have interesting applications in fundamental studies of carrier transport, or in so-called ‘valleytronics.’

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